Surface Energy Anisotropy Mediated Grain Rotation Yields Strong Texture in Low Symmetry Intermetallic Compounds

ABSTRACT Sub‐100 nm grains and strong deformation texture in low‐symmetry intermetallic compounds (LSICs) cannot be achieved by conventional mechanisms like slip, twinning, and dissolution–precipitation. Using Nd 2 Fe 14 B as a model LSIC, a novel texture formation mechanism driven by grain surface energy anisotropy (GSEA) is proposed. Ab‐initio calculations revealed a size‐dependent driving force for grain rotation, in which GSEA dominates below ∼45 nm, while GSEA and elastic strain energy anisotropy co‐operate between ∼45 and ∼892 nm. In this mechanism, platelet nanograins induced by GSEA undergo orientation‐convergent Jeffery orbit rotation in the strain flow, and texture initially forms, which is strengthened by the GSEA‐driven reduction of high‐energy grain boundaries. A low‐temperature and low‐strain‐rate deformation process is adopted to suppress grain growth and activate diffusion creep, maintaining the GSEA‐dominant size regime and enabling continuous strain flow to realize ultrastrong texture within sub‐100 nm grains. Precession electron diffraction, atom probe tomography, and transmission electron microscopy confirm three texture evolution stages: (i) formation of platelets, (ii) platelet alignment, and (iii) texture strengthening. An Nd 2 Fe 14 B magnet with ∼75 nm grain thickness and 99.6% c‐axis texture is achieved through this GSEA‐based mechanism. This work establishes a generalizable texture mechanism for nanocrystalline LSICs and provides a scalable route for ultrahigh‐performance intermetallic materials.